It was with a flurry of exultation that free-spirited Romantic poet Lord Byron wrote of how man’s control “stops with the shore”. Hong Kong’s underwater archaeologists, however, looking to discover, document and preserve relics of the city’s maritime past, have been less exalted to find the same applies to concern for local heritage.

Although heritage conservation has become a focal point in public discourse in Hong Kong, Bill Jeffery, leader of the Hong Kong Underwater Heritage Group, says: “Archaeology tends to stop at the waterline, but history does not.”

This summer, two significant artefacts were recovered by the group in waters around Basalt Island and High Island. One, a granite anchor stock suspected to date from the Song dynasty (960-1279), is believed to be Hong Kong’s oldest marine artefact. The other is a 19th-century cannonade.

The city is preparing to host the third Asia-Pacific Regional Conference on Underwater Heritage next year, but experts say Hong Kong still has not fully embraced its maritime legacy, and has a long way to go before its recovered undersea heritage can match that of Hawaii and the Philippines – both previous hosts of the conference.

Hong Kong has laws mandating heritage assessments, yet they often fall by the wayside. Professor Steven Gallagher, an expert in heritage law at Chinese University, says developers’ interests often trump environmental or heritage concerns locally.

He points to the discovery of the HMS Tamar – a British navy troopship from 1897 until it was scuttled during the Battle of Hong Kong in 1941. The government reacted with incredulity when its remains were found during reclamation work for the Central-Wan Chai Bypass last year. Fearing the development would be delayed, the wreckage was towed to an undisclosed location, flying in the face of archaeological convention that demands wrecks, at least initially, remain in situ.

The affair baffled local historians, who showed that the wreckage was clearly marked on hydrographic charts. Like every capital project since the Environmental Impact Ordinance was passed in 1998, the reclamation project would have had to pass a vigorous assessment process that, for nearly a decade, has also included a Heritage Impact Assessment. The wreck should have been retrieved at the earliest planning stage, they say.

Environmental and heritage impact assessments have been carried out in Hong Kong since 1998 and 2007, respectively. Yet not a single item of historical value has been found underwater in official searches. Over the past 18 years, close to 140 marine archaeological investigations have been completed in Hong Kong waters – all to no avail.

Gallagher is surprised. After all, the city was built on its proximity to the sea and, as it prospered, joined the ranks of New York, Cape Town, Shanghai and other grand port cities. From pirates to fishermen and shipping magnates, many Hongkongers have earned a living from the surrounding waters, he says.

To veteran archaeologist William Meacham, however, the underwhelming results are no mystery, given that underwater investigations are not strategic and are more often than not driven by development rather than academic research.

In 1970s, Meacham was among archaeologists who were initially denied access to a Ming dynasty junk found in the drained seabed that was to become the High Island Reservoir, despite having initially been given the green light. Developers only allowed the group access after local media reports on the issue caused a public outcry, he says.

Without strategically targeting areas suspected to be rich in finds, Meacham believes government-mandated investigations are little more than an “underwater wild goose chase”.

“No one’s ever done an underwater survey of the entire territory or even drawn up a strategy,” Meacham says, decrying the “piecemeal approach” taken.

The Heritage Group maintains a catalogue of 280 sites of interest in Hong Kong’s territorial waters. Yet according to Jeffery, also assistant professor of anthropology at University of Guam, only about 20 sites have actually been surveyed and just a few were investigated for research purposes rather than looming coastal development.

Whereas in most countries looting by treasure-hunters is the sole concern, the greatest danger to underwater heritage in Hong Kong comes from successive waves of infrastructure projects that disturb the seabed – or reclaim it entirely – he says.

Although the city’s 140 impact assessments have looked at large tracts of the sea floor, they could be just the narrow band beneath a submarine cable stretching from Cape D’Aguilar to the edge of Hong Kong waters, for example, Jeffery says. In such cases, the chances of finding anything using side-scanner radar – which picks up anomalies on the surface but reveals little of what lies buried in the seabed – are astronomically low, he says.

All of the group’s discoveries so far have been in the eastern waters, particularly in the Sai Kung area where marine traffic is sparsest and visibility is greatest. But conservationist and Heritage Group member Paul Harrison, tasked with preparing the group’s treasure trove for display in the Hong Kong Maritime Museum, believes it would be more interesting to search the waters west of Victoria Harbour, where cargo-laden boats have been charting a course upriver to and from Guangzhou for centuries, and sediment flowing downriver could mean there are better preserved artefacts deep in the soft, silty seabed.

Harrison says it’s encouraging that Hongkongers are becoming more interested in their own history, but they should be appreciating more than just old buildings. “Hong Kong is two-thirds water,” he says. “Most of us are here because of it being a harbour. We need to look beyond the land and see Hong Kong as the sea as well.”

Reticence about sharing data also muddies the water for local researchers. The group’s database of sites draws not on data from Hong Kong’s Marine Department but from the UK Hydrographic Office, located some 10,000 kilometres away.

Local authorities maintain a similar inventory of shipwrecks, obstructions and other navigation hazards, but it’s not available to the public and there is no channel for the two sides to collate their findings.

Without the level of support from local authorities available in Europe, Australia, Taiwan or mainland China – where official bodies are tasked with exploration and regulation – Jeffery and his group have charted a different course: mobilising local divers to help locate relics.

In addition to the anchor stock and cannonade – the latter sighted by a local diver – other artefacts, such as a stone lion dropped in the sea just meters from Tap Mun’s Tin Hau Temple, would not even have registered on hydrographic surveys since they rest in shallow waters abutting the coastline, unnavigable to the deep-keeled ships that rely on such charts, Jeffery says.

Teaching more divers how to identify potential relics on their fun dives has therefore become a top priority for the group, which runs training programmes accredited by the UK-based Nautical Archaeology Society aimed at nurturing local expertise. Its database of sites is freely available online and the group encourages others to join in the treasure hunt beneath the waves.

“Hong Kong is said to have 70,000 divers,” Jeffery says. “Even if you just get 10 per cent of them diving in Hong Kong, that’s a lot of eyes.” So far, about 60 divers have participated in Jeffery’s training programmes, but keeping them committed in spite of their day jobs has yielded only a handful of diehards, he added.

There is no financial incentive, so amateur divers must be driven by a genuine interest in local heritage protection. The 1976 Antiquities and Monuments Ordinance states that sites predating 1800 (like the anchor stock, for example) are owned by the government. For more contemporary finds, the matter is decided on a case by case basis. If no one claims a wreck, ownership automatically reverts to the government.

Marco Li is one of the group’s amateur diving diehards. He had no archaeological training before he joined Jeffery’s introduction classes, but has since become a core member of the group.

Hidden away in shallows unfrequented by most local divers, discoveries such as the Sai Kung canonade are still a rare stroke of luck for Li and his fellow volunteers. Although visibility there is better than elsewhere in Hong Kong, on the day they excavated the anchor stock they could barely see a metre ahead. “You wouldn’t really want to go diving there,” he admits.

In spite of the many challenges to maritime archaeology in Hong Kong, Li maintains that the city’s murky waters are “a potential gold mine” – and possibly a boon to local tourism, diving, and awareness of both Hong Kong’s cultural and natural inheritance.

“If we can provide divers with the understanding and knowledge to identify artefacts,” he says. “Maybe they won’t all flock to the Philippines or Hawaii. Maybe they can start looking for treasures in their own backyard instead.”